Fundamental Research On UV-LIGA-Micro-EDM Technology

MEMS(Micro Electromechanical System) technology has been paid the most attention to by academe,industrial field and governments.It has been applied in many fields such as information,precision machine,automobile,aeronautics and astronautics,biology and medicine and national defence. MEMS and micro/meso-structures & -devices are produced by microfabrication technology and their key to realization is also the microfabrication technique. UV-LIGA, which takes SU-8 resist as photosensitive material and ultraviolet light as exposure energy and adopts LIGA's process concept , is a new high-aspect-ratio 3D-microstructure technique. It has many advantages over other microfabriction technology including:low machine cost,high resist mould fabrication quality,easy to control and convenient for producing batchedly.UV-LIGA has been a research hotspot in the microfabrication field in these years. SU-8 resist has outstanding mechanical,optical and chemical performance. LIGA(LIthograpie,Galvanoformung,Abformung) was first developed in Germany and it includes three main processing steps:X-ray photography,electroforming and moulding. MicroEDM(Micro Electrodischarge Machining),which has low machine cost and large material's selection range, is a flexible and non-contacting microfabrication method and has many especial process advantages in microfabrication field,especial in fabricating metal micro/meso-structures & -devices with excellent or especial material performance.UV-LIGA-Micro EDM which combines UV-LIGA and MicroEDM is a novel hybrid microfabrication innovation,it adopts their respective processing advantages and is expected to micromachine MEMS and micro/meso-structures & -devices with complex shapes, excellent or especial material performance batchedly.This dissertation was supported by National Natural Science Foundation (50375073)and Jiangsu Province Natural Science Foundation(BK2002206,BK200421413),and it discussed and studied some technology basises and process keys centring on UV-LIGA and its combination with MicroEDM microfabricating micro/meso-structures & -devices.This dissertation consisted of seven chapters,including:The first chapter of this dissertation overviewed the research status and technology keys of UV-LIGA and UV-LIGA-MicroEDM hybrid microfabrication,it also depicted the research tasks of the present dessertation。In the second chapter,the diessertation described process basis and technique keys to all process steps of SU-8 resist photography,and then studied experimentally and optimized process conditions and parameters of some process steps including before-exposure bake,exposure and post-exposure bake in order to fabricate resist moulds in height 100~200μmon metal substrate.Experimental results showed it was helpful to improve resist mould quality if taking the following measures:reducing before- and post-exposure bake degree and increasing exposure energy moderately and interdependently,adding some accessorial steps such as removing gas in resist with ultrasound stirring,placing in air for a few minutes between the steps,cooling resist in the closed stove.It also analysed the influence of ultrasound power of resist development on microstructure quality of positive and negative resist mould,and then picked out respective appropriate ultrasound power.Experimental results indicated that ultrasound power of development of positive resist mould should be...